1. Field of the Invention
The present invention relates to liquid ejection heads and liquid ejection apparatuses for ejecting liquid.
2. Description of the Related Art
An ink-jet recording head, which is a typical liquid ejection head, and an ink-jet recording apparatus, to which the ink-jet recording head is attached, will be described. FIG. 13A is a schematic perspective view showing an ink-jet recording head 1000, and FIG. 13B is a sectional view showing a part of the cross section taken along line XIIIB-XIIIB in FIG. 13A.
The ink-jet recording head 1000 includes a substrate (hereinafter also referred to as a “recording element substrate” 1101) having a plurality of ink-ejection ports 1102 through which ink is ejected and a supporting member 1500. The recording element substrate 1101 is formed of a silicon substrate 1108, on which energy generating elements 1103 that generate energy for ejecting ink are provided, and an orifice plate 1106 having the ink-ejection ports 1102. The silicon substrate 1108 and the orifice plate 1106 are bonded together. The supporting member 1500 has an opening 1600 surrounding the recording element substrate 1101. The recording element substrate 1101 is accommodated in the opening 1600 and is bonded to the supporting member 1500. Furthermore, an electrical wiring member 1400 that is electrically connected to the recording element substrate 1101 is disposed on the top surface of the supporting member 1500 and is bonded thereto. A portion around the recording element substrate 1101, i.e., a recess between the recording element substrate 1101 and the supporting member 1500, is provided with a sealing material 2000.
If the sealing material 2000 has a high coefficient of linear expansion, a stress is generated due to expansion and contraction caused by a change in temperature in the fabrication process or a change in temperature occurring depending on the operating environment of the product. Then, as shown by arrows α in FIG. 13B, an external force is applied to the recording element substrate 1101. As a result, the orifice plate 1106 may be separated from the silicon substrate 1108, or the recording element substrate 1101 may be deformed or cracked.
U.S. Patent Application Publication No. 2008/0291243 discloses an ink-jet recording apparatus employing special recording-condition recovery means (hereinafter also referred to as a “recovery means”). An ink-jet recording apparatus produces fine ink droplets (ink mist) when ejecting ink from the ink-ejection ports 1102. Such ink droplets or paper dust may deposit on the ejection port surface of the recording element substrate 1101. Such ink droplets or paper dust deposited around the ejection ports 1102 may cause an ink ejection defect, which may degrade the recording quality. To counter this, typically, recovery means for removing ink droplets and dust is used, in which the ejection port surface of the recording element substrate 1101 is wiped by a wiping member made of an elastic material, such as rubber (hereinafter also referred to as “wiping”). Typically, in wiping, the recording element substrate 1101 is wiped by a single wiping member.
A possible configuration for reducing the risk of the above problem caused by an external force applied to the recording element substrate 1101 due to a stress generated by the sealing material is that the recess between the recording element substrate 1101 and the supporting member 1500 is not provided with a sealing material. However, if the recess is not provided with a sealing material, ink deposited on the ejection port surface may enter the recess between the recording element substrate and the supporting member when wiped by the wiping member, and the ink may remain in the recess. If the ink remaining in the recess falls on a sheet surface during a recording operation, the recording quality may be degraded.